Ted S posted:I have a Lionel 6-11203 Berk that will coast about 30" when power is cut from full speed. I have no idea whether it has supercaps, and no knowledge of the circuit design.
No supercaps in that model, I can assure you. That one is an early Legacy with the modular boards, I've worked on lots of that generation. It does have a pair of flywheels, one on each end of the motor. And of course, as you mentioned, the back-driveable gears.
ctr posted:This drop out problem is especially annoying when running in Lashup mode. The second engine provides enough momentum to push through electrical discontinuities--but the first engine drops out of DCS mode and comes up in Conventional (stopped.) So one engine is pushing against a dead stopped engine. Not good!
But the good news is the both engines physically make it across the unpowered gap to reach powered track. Thus, it suggests a larger supercap - for the purpose of keeping the electronics alive and in DCS command-mode - is indeed worth pursuing. I guess you already knew this. I didn't know this. Do the right thing before doing things right!
RJR posted:Stan, trying to recall a few years ago when I was discussing this with MTH, I think they were shooting for >2 seconds; certainly not less.
As I recall, back in the PS2 era some of us made electrical measurements to size a DIY battery-replacement supercap that could run the shutdown sequence. I'm pretty sure we were shooting for closer to 10 sec than 2 sec.
gunrunnerjohn posted:...Oh, and the 44-ton engine does indeed drop out if you do a couple quick reverses in conventional mode unless you're very quick on the button.
Ahh. Useful field report. So if that >2 sec target is the keep-alive time from a fully-charged supercap on a stationary engine, some margin (larger supercap) must be added to take into account a moving engine which might encounter two gaps close together. It makes it thru the first gap (electronics stays alive), but now the supercap is partially depleted and needs many seconds to charge back to full. But if it hits the 2nd gap before the energy is topped off, then game over.
Stan, do remember that this is not the PS3 board found in O-gauge diesels, but has been called the S gauge board. Perhaps (a WAG), the charging cicuit is of lesser capability and MTH feared a larger supercap would strain it when the supercap was discharged???????
I wish some tech could get me this board if it would fit into the Lionel trackmobile! 
I thought of the HO version but that might be strictly DC? Maybe the MTH Marklin version?
Perhaps I need another cup of coffee, but if the boards in question have two ~3F supercaps in series (i.e., 1.5F effective capacitance) as GRJ mentioned and nominally are holding 5V, putting aside some of the complexity, using the formula Capacitance = Amp seconds/voltage we should have something akin to 7.5 amp-seconds of charge available. That’s a lot of stored energy. Either that board draws way more current than I would have suspected or that energy is going somewhere other than to power the board’s electronics. Has anyone ever measured what the board draws?
Remember that they may only be able to use the stored energy down to 3.5 volts or so, that cuts way down on the amount of energy you have available.
I faced the same issue when designing my YLB - RailSounds Battery Replacement, my solution was to use a switching supply that could run in input power down to 2 VDC to extract more energy from the supercap. I don't know what the circuitry on the PS/3 board does, but I can run the Railsounds audio for 8-10 seconds on the YLB from a full charge of a 1.5F supercap.
gunrunnerjohn posted:Remember that they may only be able to use the stored energy down to 3.5 volts or so, that cuts way down on the amount of energy you have available.
I faced the same issue when designing my YLB - RailSounds Battery Replacement, my solution was to use a switching supply that could run in input power down to 2 VDC to extract more energy from the supercap. I don't know what the circuitry on the PS/3 board does, but I can run the Railsounds audio for 8-10 seconds on the YLB from a full charge of a 1.5F supercap.
Hehe, that was one of the "putting aside some of the complexity" items. Without having one of the boards, I sorta assumed that there was a small boost converter in the circuit to maintain 5V out as the voltage within the supercaps drops (much like you designed). Perhaps it doesn't - and that's the inherent problem.
My supposition, looking at it from a distance, is that even accounting for various losses and such 1.5F should store enough energy to drive a small solid state board for at least 10 seconds (and certainly more than the 2 seconds you reported) without much problem. Perhaps, though, it's drawing more than I would expect due to the radio and/or speaker?
Can anyone give me the dimensions of the board inside this 44 ton engine?
I would like to use it in another small switcher if it fits. Maybe the dimension of the truck's centers as a picture shows the board fits in between the motors.
Understand your wish, E.Joe. I'd like to try to shoehorn one into an MTH Docksider. I am told the HO Board is good up to 1-amp; I have no idea what an HO PS3 loco motor pulls. My Docksider usually pulls under 1 amp, but occasionally goes over.
GRJ, in your opinion as an electronics guru, would increasing the supercap to, say, the Digikey 2.5F you got me to use with my PS2 locos, overstress a charging circuit. Certainly, it could be fit into a 44T in place of what's there. But there must be some reason why MTH has not done that.
Well, I suspect that more capacitance "shouldn't" be an issue, but that's only a supposition on my part, I have no idea what the actual circuit driving it is. A supercap, be it 1.5F or 2.5F looks pretty close to a short circuit for a short time when totally discharged. As it charges, the current would go down. I'd like to know what value those caps in the 44-ton locomotive actually are.
GRJ, now I'm a bit confused, because an earlier post seems to say you had set forth the capacity.
I'd like to know what value those caps in the 44-ton locomotive actually are.
They are 1F @2.5v. 2each used.
RJR posted:GRJ, now I'm a bit confused, because an earlier post seems to say you had set forth the capacity.
I made an educated guess based on the size and voltage.
Allen Glenney posted:I'd like to know what value those caps in the 44-ton locomotive actually are.
They are 1F @2.5v. 2each used.
WOW! No wonder why it's a problem! You end up with 0.5F when you connect these in series. I actually thought they'd be larger! The mystery is solved, the standard O-gauge PS/3 board has 5F caps, and in series they yield 2.5F! 
So, with five times less storage capacity, it's little wonder why we're having a problem with the 44-ton locomotive!
GRJ, in your expert opinion, would a single Digikey 1.5F be an effective SAFE substitute for this pair. Or even a 1.0F is there is one?
I wonder why in the O-gauge board MTH didn't use a supercap the size of the Digikeys rather than the two large ones.
Thanks, Allen.
Well, when MTH added capacitance to yours, it would be instructive to know what they added. 
I'm shocked to find they're that small in that locomotive, I expected them to be larger. A larger cap would probably take longer to charge at the least, but I honestly don't know if the board used here would support a specific size. MTH knows I suspect. 
"Can anyone give me the dimensions of the board inside this 44 ton engine?"
61mm x25mm x18mm h
OK, so one of us needs to contact MTH to see if anyone there can in fact specify what larger capacitor would not overtax the circuitry.
Given that I gave never heard back from MTH on any of my inquiries via email or the website, I am going to leave that task to someone else. But please, report back here when the answer is in hand.
Thanks, Allen.
Thanks for the dimensions and cap values Allen, that helps. I agree, it would be nice to know from MTH if larger caps are a realistic option.
GRJ, I's like to take the 44T apart for that info and other reasons (board size), but my sledge hammer is a bit dirty so I might mar the finish (& my fingers are clumsy) Maybe I'll bight the bullet.
But for right now, we having so much rain and local flooding, I'll I have to turn to finishing my ark. "Lord, what's a cubit?"
RJR posted:"Lord, what's a cubit?"
Here you go. Do you have short arms or long arms? 
Allen Glenney posted:"Can anyone give me the dimensions of the board inside this 44 ton engine?"
61mm x25mm x18mm h
Thank you!
If you haven't heard the recently-disgraced comedian's monologue on orders to build the ark, you've mixed a great conversation.
I do believe that if the 44T has two pairs of those supercaps, the problems are over, as is the warranty.
I only see one pair of them in the pictures. It would make no sense to put in two pairs, with a lot less volume, you could simply have two larger capacity caps and solve the problem.
gunrunnerjohn posted:RJR posted:"Lord, what's a cubit?"
Here you go.
cubit
noun: cubit; plural noun: cubits; noun: long cubit; plural noun: long cubits
I think the answer you were looking for is:
God: ”Let me see, a cubit, I used to know that one. Never mind that now. I need you to collect two of every animal, male and female, and put them into the aaaark.”
Noah: “Riiiight. Who is this really?”
Did anyone solve the problem of the capacitor on the 44 ton engine? When powering up the engine just set there for about 10 seconds. Then it takes off in conventional mode. Then i have to shut down the power before it fly off the track
Truthfully, that sounds like a malfunction of your 44-Ton engine. Mine certainly doesn't do that, it's major issue is it doesn't traverse switches all that well, that's a poor continuity issue with the wheels to the frame.
Thanks Well i guess know one knows how to fix the problem.
@santa fe posted:Thanks Well i guess know one knows how to fix the problem.
I think we'd first have to identify what the root of the problem is. Since that doesn't sound like the default behavior of the engine, I'd first want to be sure what problem we're fixing.
Doesn't sound like a supercap problem.
Santa Fe, what you’re describing has nothing to do with the undersized capacitor described in this thread. The problem others have expressed is how the capacitor doesn’t hold enough power to complete the shutdown sound sequence or roll through electrical interruptions.
Your problem is different. So start by describing in more detail the circumstances. What power source are you using? How high are you setting the throttle on startup? Have you tested it in command mode? Have you tried cleaning the track and electrical pickup shoes? Has it worked like this since your first use?
Your description so far is inconsistent with how the locomotive is designed to operate. My unit takes about 3 seconds to power up after I turn on the transformer. And, as intended, it starts in neutral. Only after sequencing the direction electronics does it move forward. And my unit has very good slow-speed operation. I only need to apply about six volts to get it moving at a nice slow speed.
I have a Z4000 transformer and a Tiu unit.
I put the engine on the track. Then i starts it up. It runs fine. But when running around the layout if i hit a dirty spot on the track it would come to a dead stop. If it would start up before I get my hand held to started it. It will take off in conventional mode.
This engine ran fine until lately and I always run it in command mode. I have clean track and roller and wheels. But I don't run this engine alot. Maybe that could be the problem?
@santa fe posted:This engine ran fine until lately and I always run it in command mode. I have clean track and roller and wheels. But I don't run this engine alot. Maybe that could be the problem?
If it used to run fine and not now, something about the engine or the layout has clearly changed.
@santa fe posted:I put the engine on the track. Then i starts it up. It runs fine. But when running around the layout if i hit a dirty spot on the track it would come to a dead stop. If it would start up before I get my hand held to started it. It will take off in conventional mode.
When my 44-Ton engine stalls on a switch, when it comes back up, it's in conventional mode, but it doesn't take off.
I fixed that by adding a WatchDog Generator box to my mainline so that any power interruption will come up and see a WD to come back up in command mode.
I fired up my MTH 44-Ton locomotive to demo this, and for some reason it ran perfectly around across all the switches, etc. It must like the rest on the shelf! 
I am having a hard time to find someone to work on the MTH PRODUCT here in California. Do anyone have a favorite Train shop to work on MTH TRAINS and do the job right.?
@santa fe posted:I am having a hard time to find someone to work on the MTH PRODUCT here in California. Do anyone have a favorite Train shop to work on MTH TRAINS and do the job right.?
California is a big place (unless you are from Alaska or Texas).
You might give a general idea of where you are.
I am in the north of California
@santa fe posted:I am in the north of California
I presume you're looking for a place you can drive to without shipping? If so, maybe a slightly better location might be in order.
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